NEW YORK (Variety) - Claire Danes has replaced newcomer Sophia Bush in a pivotal role in "Terminator 3: Rise of the Machines," almost four weeks after the costly Arnold Schwarzenegger sci-fi picture started filming.

Danes started work Sunday, taking over as the romantic interest of John Conner (Nick Stahl), who is now in his 20s and once again partnered with his muscular cyborg pal while trying to elude a more advanced TX model robot bent on terminating him to change the future (newcomer Kristanna Loken). Filming on the 100-day shoot began April 15.

Director Jonathan Mostow felt that Bush, who recently co-starred in "National Lampoon's Van Wilder," seemed a bit young for the part. Danes is 23. [..]

The Intermedia Films-financed drama's $155 million-$170 million budget was the highest ever at greenlight stage, with Schwarzenegger pulling down a $30 million payday. The film is expected to be a big summer 2003 domestic entry for Warner Bros.; Sony will handle most foreign territories.